I've been there twice - once at night, and another time at sunset for a breathtaking panoramic view of Las Vegas both in the day and at night. Of course, Vegas is always prettier at night. Still, watching the sunset is always a beautiful experience....
As for the rides - I've always been a fan of thrill rides... now pair that with hanging off the edge of a building as you see the city below you or being shot 160 feet in the air at 45 miles per hour as you overlook the city.
I personally think it's well worth the $30.